The present invention is generally directed to surgical instruments and procedures, and more particularly to a vascular dilator for controlling blood flow in a blood vessel.
Massive bleeding from an arterial or venous blood vessel is one of the major causes of death in acute trauma. In addition, massive bleeding from ruptured aneurysm of an abdominal aorta or thoracic aorta is the usual mode of death for these patients. It is estimated that about 80% of ruptured aneurysm occurs in an abdominal aorta (FIG. 3) and about 20% in a thoracic aorta (FIG. 2). Iatrogenic cause of massive bleeding from perforation or rupture of a major blood vessel can also be a cause of mortality and morbidity from this incident.
Following rupture of an abdominal aortic aneurysm, the mortality from this condition has been traditionally at least 50% of those patients who reach the hospital and are taken to surgery or repair of the aneurysm. Recent advances in the management of ruptured abdominal aortic aneurysms, including balloon control of bleeding from the aorta and, when possible, endovascular repair of the abdominal aortic aneurysm, rather than open repair, has shown encouraging improvement in the mortality and morbidity of this condition. Recent reports have suggested mortality from ruptured abdominal aortic aneurysms in the order of 20-25%, compared with the previous 50%. Morbidity is also a fraction of what traditionally had been the case with open repair.
Emerging surgical literature would suggest that early balloon control of the aorta in a patient with massive bleeding from a ruptured abdominal aortic aneurysm, results in marked improvement in survival, even in those patients who ultimately undergo open surgical repair of the aneurysm because the anatomy of the aneurysm did not lend itself to endovascular repair.
Referring to FIGS. 1-7, conventionally, when a patient (P) with, for example, a ruptured abdominal aortic aneurysm (AAA) arrives at the emergency room of an hospital, he/she undergoes an expeditious CT scan to prove the condition. Once proven, the patient is whisked to the operating room and, under the current approach of early balloon control of the aorta, the femoral artery (FA) in the groin is punctured under ultrasound guidance and a guidewire (GW) is advanced under fluoroscopic guidance into the abdominal aorta (AA) above the source of bleeding or bleeding point (BP). A large introducer sheath (IS) and a dilator (D) complex is then advanced over the wire into the aorta (AA). (This dilator and sheath complex is typically long enough to allow a balloon (B) of a catheter to occlude the aorta above the source of bleeding.) Traditionally, when the patient has a ruptured abdominal aortic aneurysm, a 12-French sheath (IS) 45 cm long with an inner dilator (D) in place, is advanced over the guidewire (GW) (FIG. 5). The dilator (D) is next removed, leaving the guidewire and sheath in place (FIG. 6). A large balloon catheter (BC) is then fed over the guidewire (GW), through the sheath (IS), and then inflated in the aorta above the source of bleeding (FIG. 7). The 45 cm long sheath helps hold the balloon (B) in place to prevent it from being pushed down with each beat of the heart.
Once the aorta is controlled, the patient is fully resuscitated with blood and blood products until normal hemodynamic parameters are obtained. Repair of the aorta can now proceed as appropriate based on the anatomy of the pathologic process. If endovascular repair is possible, this is ideal. If endovascular repair is not possible, then open repair can be performed. Once the abdomen is opened, the aorta is controlled in a standard fashion. Once a clamp is placed on the aorta, the balloon is removed along with the sheath. Open repair of the abdominal aortic aneurysm can then be performed in standard manner.
The above technique/procedure can be applied to any major blood vessel in the body that is injured or ruptured for a variety of reasons. This is particularly relevant in cases of massive venous bleeding, such as a tear of the vena cava, which can occur in acute traumatic situations, and is frequently the cause of death in such individuals. Massive pelvic injury and many abdominal injuries lead to demise of the patient on account of massive venous bleeding. The same technique/procedure of balloon control of the vena cava, or a major vein, both above and below the site of injury, would be lifesaving.
Various catheters, dilators, and introducer sheaths are currently available as shown in U.S. Pat. Nos. 4,540,404; 4,909,798; 5,092,857; 5,669,881; 5,830,125; 6,537,247; 6,733,474; 2002/0183777; 2008/0065011; and 2010/0022948.